Crests and shields are a popular project. You can do these in paint and
have the kids develop four symbols that represent themselves and their
interests/hobbies. Or you can do them on cardboard with glue (so they're
3-D), cover them with aluminum foil, paint them with show polish and buff
them. This will make them look like cast metal.

Another good project is castles which can be made from heavy tag board.
First I teach the kids how to make basic 3-D shapes from heavy paper like
cones, pyramids and cubes. Then they make a castle made from these
building block. Tey to use a low temp glue gun for the "blocks". The kids
get frustrated using white glue to hold the shapes closed. Kids can work
on these in small groups to make bigger castles.